Change vehicle target method

Question

I created a method changeTarget in the TraCICommandInterface.cc file where I used the chageTarget TraCI command to change the destination. I want to know whether it is a correct implementation or not and also if the nodeId mentioned in the method is the same as the nodeId of TraCICommandInterface.h. So can I use the nodeId or do I need to use the getexternalId() method to get the vehicle id?

void TraCICommandInterface::Vehicle::changeTarget(std::string roadId) {
    uint8_t variableId = CMD_CHANGETARGET;
    uint8_t variableType = TYPE_COMPOUND;
    uint8_t edgeIdT = TYPE_STRING;
    std::string edgeId = roadId;
    TraCIBuffer buf = connection->query(CMD_SET_VEHICLE_VARIABLE, TraCIBuffer() << variableId << nodeId << variableType << edgeId<<edgeIdT);
    ASSERT(buf.eof());
}

Answer 1

No, it is not correct. The type should always go in front of the value and you don't need a compound here. So something like the following:

uint8_t variableId = CMD_CHANGETARGET;
uint8_t edgeIdT = TYPE_STRING;
TraCIBuffer buf = connection->query(CMD_SET_VEHICLE_VARIABLE, TraCIBuffer() << variableId << nodeId << edgeIdT << roadId);